Journal of Materials Chemistry Blog

Carbon nanotubes from short hydrocarbon templates. Energy analysis of the Diels–Alder cycloaddition/rearomatization growth strategy
Eric H. Fort and Lawrence T. Scott
J. Mater. Chem., 2011, Advance Article
DOI: 10.1039/C0JM02517H, Paper

In this paper by Eric Fort and Lawrence Scott, aromatic hydrocarbon belts and hemispherical end-caps of varying length and diameter are evaluated computationally as possible templates from which carbon nanotubes might be grown by the Diels-Alder cycloaddition/rearomatization strategy.  The team from Boston College in the USA found that the Diels–Alder reactivity of nanotube template rims was relatively unaffected by the presence or absence of a cap on the other end.

Interested in knowing more? Read for free until November 30^th!

Ultra-narrow WS₂ nanoribbons encapsulated in carbon nanotubes
Zhiyong Wang, Keke Zhao, Hong Li, Zheng Liu, Zujin Shi, Jing Lu, Kazu Suenaga, Soon-Kil Joung, Toshiya Okazaki, Zhaoxia Jin, Zhennan Gu, Zhengxiang Gao and Sumio Iijima
J. Mater. Chem., 2011, Advance Article
DOI: 10.1039/C0JM02821E, Paper

A team from China and Japan report the synthesis via chemical reaction in the interior space of carbon nanotubes of zigzag-edged WS₂ nanoribbons with widths down to 1–3 nm and layer numbers of one to three. Layered WS₂ nanostructures are of both fundamental and technological interest. The widths of currently synthesized WS₂ ribbons are in the microscale but by using single-walled carbon nanotubes and double-walled carbon nanotubes as templates this team demonstrate that ribbons in the nanoscale are possible. 

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Fabrication of covalently crosslinked and amine-reactive microcapsules by reactive layer-by-layer assembly of azlactone-containing polymer multilayers on sacrificial microparticle templates
Eric M. Saurer, Ryan M. Flessner, Maren E. Buck and David M. Lynn
J. Mater. Chem., 2010, Advance Article
DOI: 10.1039/C0JM02633F, Paper

David Lynn and colleagues from the University of Wisconsin demonstrate an approach to the fabrication of covalently crosslinked and amine-reactive microcapsules by the ‘reactive’ layer-by-layer fabrication of azlactone-functionalized polymer multilayers on the surfaces of sacrificial microparticle templates.  These microcapsules have potential use in a wide range of fields, including catalysis, drug and gene delivery, imaging, and biomedical research.

Interested in knowing more? Read for free until November 30^th!

This ‘Hot Article’ by Liang Li, Yoshio Bando, Dmitri Golberg and colleagues, reviews recent developments in the synthetic strategies and unique applications of one-dimensional (1D) nanostructure arrays based on polystyrene (PS) spheres.

Polystyrene sphere-assisted one-dimensional nanostructure arrays: synthesis and applications
Liang Li, Tianyou Zhai, Haibo Zeng, Xiaosheng Fang, Yoshio Bando and Dmitri Golberg
J. Mater. Chem., 2011, Advance Article
DOI: 10.1039/C0JM02230F, Feature Article

PS spheres can self-assemble into colloidal crystal monolayers that are currently employed as templates for the synthesis of 1D nanostructure arrays.  Compared to other classes of templates these monolayers can be easily formed and adjusted on substrates and further manipulated using subsequent growth methods.  Reported applications of PS-sphere mediated nanoarrays include field-emitters, antireflection, light-emitting diodes (LEDs), photonic crystals, surface wetting, and photocatalysis.

In this feature article, the team from the National Institute for Materials Science in Japan highlight recent developments in synthetic strategies, review emerging applications and analyse future challenges.

Read the full text here.  Free until November 24th!

A team from Oklahoma report the fabrication of non-leaching antibacterial surfaces using a single-step vapour crosslinking method.

Single-step fabrication of non-leaching antibacterial surfaces using vapor crosslinking
Yumin Ye, Qing Song and Yu Mao
J. Mater. Chem., 2010, Advance Article
DOI: 10.1039/C0JM02578J, Paper

Bactericidal surfaces are highly desirable to prevent bacteria-associated infections in hospital and health care facilities. Current surfaces are based on the release of antibacterial agents, however, leaching of antibiotics can contribute to the escalation of bacteria resistance. An alternative strategy is to create non-leaching antibacterial surfaces. The non-leaching surfaces kill bacteria on contact, which has been reported to reduce the probability of developing bacteria resistance.

Yu Mao and colleagues copolymerised vapours of dimethylaminomethylstyrene (DMAMS) and ethylene glycol diacrylate (EGDA) to produce crosslinked polymer coatings.  The tertiary amine groups in DMAMS units become partially protonated at neutral pH conditions, resulting in crosslinked coatings which have cationic charges distributed across the polymer network and kill bacteria through disruption of the bacteria membrane upon surface contact. Killing efficacy of more than 99.99% against both B. subtilis and E. coli was achieved and leaching tests indicated that the crosslinked coatings did not leach from the surface to kill bacteria and were stable after the durability tests.

Interested in knowing more?  Read the full article here.  Free until November 22nd!

Erin Murphy from the University of California reports the use of birefringence to assess damage and extent of repair in healable polymers based on the thermally reversible Diels–Alder reaction, in this ‘Hot Article’.

The return of photoelastic stress measurements: utilizing birefringence to monitor damage and repair in healable materials
Erin B. Murphy
J. Mater. Chem., 2011, Advance Article
DOI: 10.1039/C0JM02308F, Paper

Examining a transparent polymer under polarized light reveals the stress distribution throughout the sample due to the birefringence in the material arising from anisotropy, clearly indicating areas of high stress; by applying a photoelastic coating to metal and opaque composite structures, it is also possible to identify areas of stress in non-transparent materials and parts.

Herein, Erin Murphy demonstrates the application of birefringence and the principles of photoelastic stress measurements to monitor a healable polymer. By systematically monitoring the birefringence of the material under a controlled applied stress, her group have developed their own calibration curve for the analysis of isochromatic fringes in the polymers.

The birefringent property of these polymers affords the ability to analyze residual stress in a fabricated sample, in order to assess the sites most likely to fracture and to then re-design the specimen geometry and processing parameters to avoid such areas within the material.

Interested in knowing more?  Read the full article here.  Free until November 22nd!